Cartoned goods leave the factory on pallets and reside in a warehouse until purchased by a supermarket or distributor. They are taken from a warehouse rack by a robot selector or a forklift and are loaded onto a truck for transport to the retail premises. Thus the goods remain on pallets from the factory, through the warehouse, on the truck and into the supermarket. The pallets are standard size. 1200×1200 mm and a pallet load may consist of several superimposed layers of cartons. Supermarkets commonly order in multiples of pallet layers. Conventionally a pallet carries only one type of good, for example, a full load of buffer.
If an order from a supermarket is for two pallet layers of margarine, the margarine pallet will leave the warehouse with only two layers. The loader who supervises the composition of the road truck must use the road truck volume as best he may, but presently as much as 6t of the 35t load represents the timber of the pallets. This is uneconomic, the consequence of the carton by carton assembly of a customers order at the warehouse. Systems designers in the distribution business have, sought savings in records, ordering programs and software, but the physical handling of the cartons which compose the individual orders has remained unchanged for a period of years.
International pallets used in air freight do not correspond to the standard pallet in Australia and all goods must be transferred from one to the other. This is all done manually and the volume of work at airports and warehouses causes a correspondingly large number of injuries, such as repetitive strain injury (RSI).
The industry approach has been to use a stacker crane system which moves along shelving and extracts whole pallets of goods sometimes using vacuum heads carried by frames and other structures for guiding the motion of the vacuum head. Such a system is shown in U.S. Pat. Nos. 3,782,564 and 5,102,283. These systems are efficient for bulk transfers but not equipped for part pallet loads.
A forklift is versatile but the application of vacuum handling to forklifts is exemplified by U.S. Pat. No. 4,725,186 where onboard vacuum equipment working continuously is used to handle newsprint rolls. WO 97/13718 takes the handling design further by attaching vacuum pads to the front of a pallet-like structure which can be picked up by a standard forklift. When the forklift reverts to ordinary use, the special handling accessory can be removed and parked until it is needed again. Such special purpose equipment sold as an accessory is useful but not for the layer by layer problem which comes up when pallet loads are divided in wholesale grocery.
WO 01/30675 is more pertinent that the suction devices are able to handle a layer of cartons but the utilization of the equipment is not discussed.